This is a renewal application for a GI Training Grant (TG) at the Johns Hopkins University School of Medicine for the training of (A) postdoctoral fellows (MD, MD/PhD or PhD) for long-term investigative careers in basic and translational investigation in Gastroenterology. This program has strong basic science investigators in the GI Division; a formal 4 year program for training translational/clinical investigators done in collaboration with the Hopkins School of Public Health resulting in a PhD or MPH in clinical research; close interactions with Hopkins Basic Scientists; a closely knit group of scientists interested in epithelial cell and molecular biology, inflammation, fibrosis and GI cancer, neurogastroenterology, and IBD; an NIDDK Conte GI Core Center Grant ;PPGs on trafficking in epithelial cells, intestinal heavy metal transport and pancreatic development and cancer; and a U18 on enteroids as models of GI disease. The TG faculty (25) have primary appointments in the GI Division (16); Departments of Cell Biology (1); Physiology (3); other Dept of Medicine (2); Pathology (1); Oncology (2); Surgery (1); Pediatrics (1); Genetics (1). The Hopkins GI Division has several areas of expertise for research training of fellows-BASIC: studies of epithelial transport, polarization, differentiation, and trafficking of membrane proteins, actions of bacteria enterotoxins, inflammation causing fibrosis and cancer, neurogastroenterology, IBD, genes activated in pancreatic cancer and epigenetics and biomarker discovery of GI cancer. TRANSLATIONAL/CLINICAL: IBD and GI cancer biomarker discovery, confocal endoscopy in GI disease, and diversity and GI disease. A total of 5 Postdoctoral TG slots are requested per year to be used for 3-4 MD or MD/PhD and/or 1 or 2 PhD fellows. The program is for (a) 2-3 years in the laboratory or 3 years of clinical research training leading to a PhD or MPH, in addition to a clinical year not supported by the TG, and (B) a predoctoral program (~3 years) to train future basic science faculty who do basic science GI related research. All Fellows are assigned a Fellowship Committee to monitor their progress. Fellows who are thought to be successful in being prepared for investigative careers are helped to apply for K awards and appointed as junior faculty to continue career development.